Leak test instruments have applications in industries including aerospace, automotive, refrigeration, defense, oil and gas, semiconductor, and renewable (for example, solar) energy. However, for many industrial applications performing gas sampling and leak test operations is becoming more and more difficult as safety requirements increase due to the reluctance of having powered (for example, AC power) testers in sensitive or hazardous applications. For example, in some static sensitive or hazardous (e.g., flammable, poisonous) applications and with the current safety rules, powered test equipment cannot be used when electrical discharges are possible (for example, when lightning storms are in the area or when electrical motors, such as vacuum pumps, are operated), which greatly reduces production throughput.
Typical leak test instruments are bulky and require AC power and gas cylinders (for example, helium). Further, none of existing instruments incorporate the on-board capability to measure volume, a necessary parameter for calculating and interpreting pressure rise leak rates. Additionally, most of these instruments require lengthy warm-up times. Therefore, a need remains for a leak test instrument that is compact, has a short response time, is not electrically powered, and can be used in sensitive or hazardous applications.